Process of making insoles



Oct.1, 1940. H. s. LUMBARD PROCESS OF MAKING INSOLES Original Filed Feb. 3, 1940 2 Sheets-Sheet l ,4 AM, "a

Oct. 1, 1940. LUMBARD 2,216,205

PROCESS OF MAKING INSOLES 2 Sheets-Sheet 2 Original Filed Feb; 3, 1940 ea IQ Patented-Oct. i, 1940 UNITED STATES PATENT OFFICE rnocnss or MAKING INSOLES Henry G. Lumbar-d, Auburn, Maine Original applicationFebruary s, 1940, Serial o. 317,145. Divided and this application May-14,

It), Serial No. 335,050

7 Claims; (01. 12-146) 1| fact that the ideal shoe is one having suillcient thickness of sole structure to act as a cushion so that the wearer cannot feel pebbles and other irregular objects through the sole. It will be apparent that these factors tend to work against ll one another, that is to say a sole structure which is sufllciently flexible isgenerally so thin that the wearer can feel objects through the shoe.

An additional problem to be considered arises from the increased resistance encountered when Q two flexible members are secured .together in face to face contact. If a thin flexible outsole is secured to a thin flexible insole, the resulting sole structure is relatively inflexiblebecause the insole binds against the outsole when the latter u is flexed and opposes effective resistance to the action of the outsole. The most important object of my invention is to provide a novel process for rendering an insole not only flexible per se but also capable of being combined with an outa sole without offering any resistance to the action of the latter, with the result that the flexibility of the combined sole structure maybe measured by the flexibility of the outsole alone.

1 In my c'o-pending application Ser. No, 240,987 35- I' have claimed my improved insole in' combination with a shoe. In my Patent No. 2,181;'787

I have claimed the method of making insoles of this character, which comprises providing an insole blank of nearly normal outline and there- 9 after elongating it by slashing it in a particular. 111821181. The present applicationd's a division of my co-pending application Ser. No. 317,145, filed February 3, 1940 and relates to a process for making insoles wherein the opera- 45 tions are initiated ona strip of insole material and characterized by the important steps of stretching and releasing the slashed strip before I insole blanks are cut out.

The essence of my invention lies in the fact no that an insole which will meet the requirements. above discussed can only be produced if the slashing penetrates the entire thickness of the blank and also intersects the edges of the flnished sole., In view of the fact that the toe, '5 heel, and shank portions'of a shoe should be relatively stiff as compared with that portion lying in advance of the shank and behind the tip line my novel process can advantageously be applied to insole material of the type disclosed in U. S. Patents 'Nos. 2,065,405, Sewall and 2,098,502, 5 Lehner. These patents disclose sheet insole material characterized by the provision of a relatively flexible central portion and relatively stiff and inflexible side bands; insoles or midsoles may be cut from such material in such a 10 way that the toe and heel lie in the stiff side bands, whereas the central portion of the insole lies in the flexible central strip or band. My invention may be characterized as an improvement upon the processes and insoles disclosed 18 in these two patents,

In one aspect the processor my invention is characterized by the step of providing a strip of other hand across the strip under some pressure.

It will be found that the slashes do not return to their initial condition when the stretching tension is released, but assume a permanent in- .termediate open position. As a result of the slashing and stretching operations, the strip will be found to be considerably wider than' before these operations were undertaken. The longi-'-.

tudinal edges of the slashed strip are beveled, preferably before the slashing is done. Thenext step in the process is to cement solid strips to the beveled edges of the slashed strip so that the latter is then provided with relatively stiff side bands of solid insole material. From the composite sheet thus formed insoles may be dyed out with their toe and heel portions in the stiif side bands and their midportions in thtyslashed flexible'strip.

It will be evident that the operation of attaching the side bands to the central strip may be effected either before or after the slashing, stretching, and releasing operations. That is to say, a sheet of insole material may be made up of a relatively flexible central strip cemented at its longitudinal edges to side bands of relatively stilt material, the central strip being slightly narrower than ultimately desired. The slashing operation may then be carried out only .on the central strip, whereupon the entire sheet is stretched to open the slashes in the central strip and thereafter released. The total width of the sheet will be increased by reason of the permanent expansion of the slashed central strip. Furthermore the operations may be carried out on a single broad sheet of insole material, a central portion of the uniform sheet being slashed, stretched, and released 'in accordance with my invention, the marginal portions being untreated and left in their original condition. The Sewall and Lehner patents disclose the'step of slashing the central portion of a sheet of insole material, but they do not disclose slashing of the type which willpermit permanent expan sion of the central portion or which acts in such a way that upon stretching and releasing the sheet-the central portion is left in a permanent expanded condition with the slashes in an intermediate open position. When the slashing is carried out according to my invention, the stretching opens the slashes to a considerable extent, and when the sheet is released, the slashes do not assume their initial condition but remain partly open, in which state their edges are freely movable and do not bind upon one an- .other. It should be noted that the permanent expansion of the central portion of the sheet results in a saving of material, since the central strip may be initially somewhat narrower than will be ultimately required, the difference being made up by the slashing and stretching operations.

Insoles manufactured according to the process described in the foregoing paragraphs display an extraordinarily high degree of flexibility when incorporated in a shoe, since the edges of the slashes have been separated by the stretching operation with the result that they arefree to go and come as the shoe is flexed, thus providing no resistance or limit to the fiexibilityof the out.- sole. Broadly speaking, shoes manufactured with insoles of this type can be rated as to flexibility by the flexibility of. the'outsole, since the resistance of the insole is negligible.

Superior cushion insoles may be manufactured by first making a slashed insole blank according to the process described above, and then bonding the'blank to a cushion having the shape of an that this final stretching of the slashed insole does not result in noticeable distortion, because the total length of the insole is only increased when I stretch the slashed strip, and then if a cushion insole is being made, I may effect a further saving in material by cutting the slashed blank-it' shorter than is required and stretch- It will be apparent that I first save material ing it to full size as it is bonded to the ply of cushion material.

It is also possible to make cushion insoles by bonding to a sheet of cushioning material a sheet of insole material which has had a portion thereof slashed, stretched, and released, and there-,

, after cutting out cushion insoles from the united sheets. 'The sheet with the slashed portion may be again stretched as it is secured to the cushion sheet in order to open the slashes further. -However, this process is more expensive than cutting out separate insole blanks from the slashed sheet and from the cushion sheet and thereafter uniting them, since less cushion material is wastediin the latter process.

It should be understood that in referring to insoles in the specification and claims of this application I do not limit myself to conventional full length insoles, and the term in all instances should be understood as including midsoles or, indeed, any piece used in the sole structure of a shoe, excluding outsoles. Furthermore, the cushion material is not necessarily co-extenslve in area with the area of the insole or midsole'to which it is secured.

The several objects and features of my inven-,

tion will be readily understood and appreciated from the following detailed description of several preferred ways in which it may be practiced, as illustrated in the accompanying drawings in which:

Fig. 1 is a view in perspective of a strip of insole material slashed according to my invention, Figs. 2, 3, and 4 are views in perspective of the slashed and stretched strip and the stiff side bands, I

Fig. 5 is a view in perspective showing an insole cut from the combined strip and side bands,

Fig. 6 is a view in perspective of a complete insole,

Fig. '7 is a view in perspective of a cushion for an insole, I I

Figs. 8 and 9 are views in cross section illustrating the combining of an insole with a cushion,

Fig. 10 is a view in perspective of a fragment of aslashed strip under stretching tension,

Fig. 11 is'a view in cross section of'an insole embodying a thin tender layer.

In carryingout the-process of my invention according to a preferred sequence of steps, I first prepare astrip IU of fibrous insole material with bevelled edges, as shown in Fig. 1, which material may consist of fibre board, paper stock, leather,

or any of the materials suitable for making insoles. The strip II! isthen provided with a number of rows of relatively short; spaced slashes or cuts I! all of which penetrate the entire thickness of the material. The slashing is carried out to intersect theend edges of the strip. i0. By grasping one side of the strip l0 and rubbing a hand across it with some pressure in a direction normal to the direction of the slashes, I stretch the strip. l0 laterally, thus increasing its area by reason of the fact that the slashes open up under tension as shown in Fig. 10. This action cannot beo'btained unless the slashes penetrate the en- -3. The width of the slashing in Figs. 3 and 10 is somewhat exaggerated for purposes of illustration. It will be apparent," however, that the edges of the'slashes are'per'manently separated and are therefore freely movable relative to one another.

, e bevelled longitudinal edges of the slashed and stretched strip ID are cemented to correspondingly bevelled edges of a pair of bands I and I6 of relatively stiff material such as fibre board so that a sheet is formed comprising the slashed and stretched central strip l0 and the stiff side bands l4. and It. The dimensions of The insole 18 may be used in the manufacture of a shoe according to any of the conventional methods of shoemaking. It will be apparent that the sequence of operations may be varied provided the slashing and stretching precede the cutting out of the insole. For example, the strip It may be secured to the side bands M and I6 before the slashing is done.- Furthermore, it is possible to slash the central portion of a sheet of homogeneous material wherein the marginal portions are relatively stiffer than the'central area merely because they are not slashed and not because their composition is different.

My invention is particularly useful in the manufacture of cushionlinsoles, and in this connection I provide a cushion 24 cut to the shape of an insole and made of ground cork and rubber or other suitable cushioning material. To effect a saving in material I may cut the insole I! a half size smaller than the cushion 24 and stretch it to the size of the cushion while cementing it thereto. In Fig. 8 I have illustrated the insole l8 superposed on the cushion 24, the insole being shorter than the cushion. In Fig. 9 the insole l8 has been stretched to coincide with the area of the cushion 24. The slashes in the latter case are, as shown, expanded more than in Fig. 8.

- Therefore -I may save half a size of insole material in each cushion insole. Obviously I may omit the second stretching step-and cut the insole full size and bond it to the cushion without stretching it again. The stretching operation which is doneto increase the insole a half size is not suflicient to distort the insole appreciably.

However, in a shoe factory of substantial size the saving of material amounts to a considerable saving over a comparatively short period.

' A sheet of cushioning material may be bonded by cement to a sheet comprising a slashed and stretched central strip with stiff side bands and flexible cushion insoles cut therefrom. However, it is more eflicient to cut the blanks separ ately and so avoid waste of cushion material.

- When a cushion is not desired and the cement facture of the shoe, I prefer to employ a layer 26 of thin, tender paper or cloth which is only stiff enough to pass through a latex coating machine without curling. After the insole l8 has been cut out it islaminated with the layer 26 which, has previously been coated with latex. The purpose ofthe layer 16 is to prevent the cement used in lasting from coming through the slashes I2 and reaching the last bottom. 'Otherwise the insole l8 would be cemented to the bot-' tom of the last, and last pulling would be diflicult if not impossible. In the shoe the material of the layer 26 break apart or give way in wear where it is bonded to the slashed portion of the insole i8 and thus have practically no stiffening, effect. The layer 26 will not lump up or come adrift in a shoe because it is cemented to the insole l8 and held in place between the insole and outsole. Furthermore the layer 26 may be cut 1 of and greatly of laminating the two togethefas shown in Fig. 11. This effects a saving in insole material. It should be pointed outthat the layer 26 will act to stiffen an insole unless the insole is slashed according to my invention. Also use'of layer 26 permits the employment of thinner material for the insole I8.

I am aware that in British Patent No. 979 of 1888 and in German Patent No. 343,037 of 1920 is disclosed a process of making soles which com-' prises cutting out a blank of indeterminate form, slashing the blank, stretching the slashed blank todistort it into the shape of a sole, and flnally thing the slashes with india rubber or other "filling material. However, these prior processes are not useful for the manufacture of insoles because it is impractical to determine in advance the sizes of soles produced by them, and the material of the blanks is so stressed and distorted that the soles produced are objectionably weakened.

My novel process is an improvement upon the aforementioned process because the insole blank, in my process, is not cut out until after the stretching operation has been accomplished. Furthermore it is important that the holes formedby slashing the sheet I and stretching it be left as free spaces in the body of the insole. The edges of the slashes must be free to move as I 3 size and then elongated to full size in the process I the sole is flexed in wear, and to press a flller into the slashes would immobilize the edges there-. diminish the flexibility of the insole.

Although a piece of material is permanently expanded somewhat when it is slashed with a bevelled knife as contemplated herein, the permanent expansion resulting from the stretching operation is greater and has important advantages of flexibility/and material saving.

My invention is not limited to the manufacture of full size insoles but is well adapted for the manufacture of forepartinsoles, midsoies, and insoles having flexible portions in the shank or toe as-well as in the forepart. The term' insole" as used in the appended claims is specifically intended to include the variations mentioned above.

Having thus described my invention what I claim as new and'desire to secure by Letters Patent of the United States is:

1. The process of making insoles which comprises providing a portion'of a sheet of insole material with a plurality of rows of short throughand-through slahes, stretching the sheet in a direction normal to the slashes to open them, releasing the sheet to permit the slashes to assume a permanent intermediate open position, and

cutting out insoles from the sheet.

2. A process of making a sole having a flexible area, which comprises providing sole material, slashing that portion of the material which is t lie in the flexible area of the finished sole, the slashes being in the form of a plurality of rows of short, spaced, through-and-through cuts extending completely across said area and intersecting the edges thereof, stretching the slashed material to open the cuts, releasing the material to allow the cuts to assume a permanent intermediate'open position, and thereafter cutting a sole from the material so that one portion of the sole includes an area made flexible by;said cuts.

'3. A process of making insoles which comprises providing a stripof' flexible insole material, securing side bands of relatively. stifl material to the to full size and the insole-l8 cut down half a longitudinal edges of saidstrip, providing said strip with a plurality 01' rows oi short, transverse, through-and-through slashes some of which intersect the ends of the strip, stretching the strip to open the slashes, releasing the strip to permit the slashes to assume a permanent part by open condition, and cutting out insoles so that portions thereof are slashed through and through from edge to edge.

4. A process of making insoles which comprises providing a central strip of a sheet of insole material with a plurality of rows oi short spaced, through-and-through slashes extending from one end of the sheet to the other, stretching the sheet laterally to expand the central strip and open the slashes, releasing the sheet to permit the slashes to assume an intermediate open position and cutting out insoles from the sheet so that each insole includes within its area a portion of the slashed central strip.

5. A process of making an insole which comprises, providing a strip of material, securing relatively stiiI side bands to said strip, providing saidstrip with a plurality of rows of short, spaced, through-and-through slashes, stretching the strip laterally to open' the slashes, releasing the strip to permit the slashes to assume a permanent intermediate open position, cutting out an insole so that a portion thereof includes material cut from the slashed strip, and bonding the insole to a cushion.

6. A process oi making an insole, which comprises, providing a strip oi material, securing relatively stifl side bands to said strip, providing said strip with a plurality of rows of short, spaced, through-and-through slashes, stretching the strip laterally to open the slashes, releasing said strip to permit the slashes to assume a permanent intermediate open position, cutting out a short insole so that a portion thereof includes material cut from the slashed strip, providing a full size cushion, stretching said insole to full size, and bonding the insole to the cushion.

7. A process for making a cushion insole which comprises provlding'the central portion of a strip with a plurality of rows of spaced through-andthrough slashes some of which intersect the ends of the strip, stretching said strip to open the slashes, releasing said strip to allow the slashes to assume an intermediate open position, cutting an insole from the strip so that a portion thereof includes material which has been slashed, and bonding the insole to a cushion.

HENRY G. LUMBARD.

CERTIFICATE OF coRREcTIoN. 7 Patent No. 2,216,205. 0ctober l,'l9)40.

HENRY c. LUHBARD. w

It is hereby certified that error appears in the printed. specification of the above numbered patent requiring cerrection as follows: Pagel g, first column, line 5, claim 5, for the words "part by" redo. --partly-- and that the said Letters Patent should be reaiwith this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sea-1ed.this 29th day of Qctober, A.- D. 19 40.

Henry Van Arsdaie, (Seal) Acting Commissioner of Patents 

